Air conditioning system



March 8, 1 93 8.

I. J. KNUDSON AIR CONDITIONING SYSTEM Filed July 25, 1935 2 Sheets-Sheet 1 March s, 1938.

l. J. KNUDSON AIR CONDITIONING SYSTEM Filed Ju1y 25, 1935 2 Sheets-Sheet 2 lNVENTOR J w BY W M ATTORNEY Patented Mar. 8, 1938 2,110,367 I CONDITIONING SYSTEM r OFFICE" Irving J. Knudsen, Kenilworth, 111., assignor to Detroit Lubricator Company, Detroit, Mich, a Corporation of Michigan Application July 25, 1935, Serlal No. 33.113

3 Claims. (Cl. 25'l-3) My invention relates generally to air conditioning systems and more particularly to control I and to provide a system of this character which is highly efficient in operation.

Another object of my'invention is to provide 10 an air conditioning system of the type having both a cooling unit and a heating unit and to provide a new and improved cooperative arrangement of the control devices therefor.

Other objects of my invention will be apparent from the following detailed description taken in connection with the accompanying drawings which form a part of the specification, and in which drawings- Figure 1 is a view showing an air conditioning 20 system embodying my invention;

Fig. 2 is a view taken in the direction of the arrows 22 of Fig. 1, and

Fig. 3 is a diagrammatic view showing the arrangement of the control devices of the sys- 25 tern in an electric circuit.

In the drawings there is shown apparatus-of an air conditioning system for conditioning the air of a room and which apparatus is preferably disposed in a recess ofa vertical wall 2 30 of a room, as shown. The recess I may be closed and the apparatus therein hidden by a closure member or panel 3 which thus cooperates with the walls defining the recess I to provide a closed compartment 4 for the air conditioning appara- 35 tus.. The panel 3 maybe attached to the wall 2 by means of screws or other suitable attaching means. In the panel 3 and preferably adiacent the upper wall of the compartment 4 there is provided a plurality of apertures 5 for the 40 passage of air from compartment 4 into the room, and in the panel 3 and preferably adjacent the floor of the room there is provided a plurality of apertures 6 for the passage of room air into compartment 4. Y

45 Disposed within the compartment 4 there is a frame for supporting the air conditioning apparatus and which is constructed, in the present instance, by spaced, end upright members 8, there being two at each end of the compartment 4 50 and connected at their upper ends by horizontal end or side cross members 9 and front and rear cross members [0. Mounted on the horizontal cross members l there are two spaced fan units enclosed in housings l2 which have air outlets, 55 as at I3, and which are arranged for discharging air into the room through the apertures in the panel 3 and for increasing the rate of air flow through chamber 4. Mounted on the horizontal cross members l0 and between the spaced fan units there is an electric motor. l5 5 arranged to drive both fans. Preferably there. is provided an opening l6 through the wall 2v for'the intake of fresh outdoor air by the fans and preferably the intake is located and leads into the compartment 4 at one end thereof and 10 adjacent the floor of the room, as shown in Fig. 1. In the present lnstance,'an extension or duct I1 is provided for connection with the intake passage I6 and has an outlet l8 disposed lv to direct the incoming air longitudinally of the 1 compartment 4. A damper. l3 may be provided in the extension or 'duct H for controlling the volume of incoming outdoor air.

Disposed within compartment 4 and beneath the fans there is a combined heater and coolerelement which comprises a cooling coil 20 and a heating coil 2|. The coils 20 and 2| preferably have a sinuous form and are arranged one above the other in the same vertical plane with the cooling coil preferably located above the heat-v ing coil. The cooling coil 20 and the heating coil 2| extend transversely through a plurality of spaced and vertically extending plate members or fins 23, which fins serve as a commoner:- tended surface for both the'heating and the cooling coils. Thefin structure includes end supporting members 25 and the structure may be supported by depending brackets 26 rigidly fixed to the cross members l0 and the end sup- .porting members 25 of the fin structure.

From the source of supply of the heating medium, which may. be a steam boiler located the basement of a building. there is a supply pipe or conduit 29 which leads into the compartment 4 and connects to one end of the heating coil 2|, as at 30. To the other end of the heating coil 2| there is connected a conduit or pipe 3| which returns to the source of supply. In the inlet line 29 there is preferably provided a manually operated valve 33 for controlling the flow of the heat conveying medium through the heating coil 2|. The valve 33 is preferably located within compartment 4 and so that it will be readily accessible upon removal of panel 3. 'Clamped in good heat transfer relation to the supply pipe 29 and preferably adjacent the inlet end of coil 2| there is a temperature responsive switch means, designated generally by the numeral 35, which controls and ispreferably in circuit with the fan motor l5, as shown diagramhereafter described.

.- vice 30, which may be an expansion valve of to the cooling coil 20.

the thermostatic type, as shown, is provided for controlling the admittance of refrigerant to the coolingooil 20 and is preferably connected in the line at the inlet of coil 20. The thermostatic expansion valve includes a temperature responsive bulb 40 connected thereto by means of a tube or conduit 4i, the bulb and tube being charged with a suitable expansible-contractible fluid such as methyl chloride. Preferably the bulb is clamped in good heat transfer relation to the suction line II and adjacent the outlet end of coil 20. Disposedin the supply line 31, between the expansion valve 39 and the condenser element, there is a solenoid valve, designated generally by the numeral 43, for controlling flow The solenoid valve 43 may be of any suitable type and is preferably located within compartment 4.

. Disposed beneath the heating and cooling element there is a container or reservoir 45 for containing water to supply artificial humidification to, the air of a room during the season when artificial humidification becomes necessary to the comfort ofpersons in the room. Water is supplied to the container 45 from asource of supply by means of a pipe or conduit 44 which, in the present instance, extends through the bottom wall of the container and leads to a valve 41, the valve 41 being controlled by a float 49 to maintain'w substantially constant level of water in the container 45. Preferably a drain drain may consist of a vertically extending pipe or conduit, as at I, which extends upwardly 'into the container to the liquid level desired. The vertically .extendingdraln pipe connectsinto. and intermediate the ends of, a inain drain pipe I. Also connected to the main drain pipe I but at the end thereof there is a second drain pipe 52 which terminates at the container bottom wall for completely. draining the container. In the drain line or pipe II there is a shut-oi! orgcontrolvalve I! positioned 'between outlet pipes II and I2 and which is closed when it is desired to maintain water in the container 4'. In the supply pipe46 there is a valve 54 to be closed when humidification is not desired and when valve 3 is open. When artificial humidification is desired the container is filled with water to the'desired level for supplying additional moisture'to the incoming air for discharge into the room. To facilitate the entraining of additional moisture by the air, there may be provided a plurality of spaced, vertically dis-.

.posed pieces or sheets of absorbing material or fabric, as at I, arranged in the path of the circulating air and with their lower ends 'disposed in the water in the container 45. The

supported at their opposite ends by brackets I having apertures for receiving the rods, the brackets being welded or otherwise secured to the end supporting membersli. L

Referring now to Fig. 3 which shows diagrammatically the arrangement of the electric circuit or circuits, including the fan motor ii, the solenoid valve 43 and the temperature responsive switch 35., the lines 58 and 58": represent the lead wires'from the main line which may be the usual llll volt line. Connected to the lead wire 58 there is a wire 51 which leads to the fan motor i5, and from the fan motorthere is-a lead wire." connected to one terminal of the switch means' 35, the lead wire 88' being connected to the other terminal of the switch means to complete the circuit. Preferably a rheostat'tt .is provided in the lead wire 51 for controlling the speed of the fans, and the rheostat maybe located on.the wall of the room or in any other suitably accessible location. Connected to'the lead wire 58 there is alead wire ll which'connects to the solenoid valve 43, and leading from the solenoid valve there is a lead wire 62 which connects to one terminal 62 of a manual switch 63,4.The manual switch il'is'shown as a double pole single throw type having one blade CI I! between the fan motor II and the automatic switch 35. The blade 83] is connected by a lead wire I! to line wire SI. Thus it will be seen that the fan motor I! and the temperature responsive switch {I that controls operation of the fan 'duringthe heating season, are in series circuit irrespective of whether the manual switch I is in open or closed position. Also, it will be seen that the solenoid valve'43' and the fan motor II will be in parallel circuit when the manual switch 63 is clos operate continuously irrespective of the operation of the temperature responsive switch 35.

A complete operation of my system is as follows: When'neither heating norcooling of the room air is desiredpif such should be the case, ,the supplying of the heating medium to the heating coil 2i may be discontinuedby means of themanual valve 33 and the supplying of refrigerant to the cooling coil may be discontinued by opening the circuit to the solenoid valve 43 by means of the manual switch 63. When it is desired to employ the heating element to heat the room or other space, the valve 33 being nor- 'mally open to permit the heating'medium to iilow'through the heating coil 2| and the circuits to lead wires SI, 88' being closed, the switch 63- is opened. when the temperature of the heating medium flowing through the supply pipe, and controlled at thesource of supply, causes the temperature responsive'switch II to operate and close the circuit to the fan motor l5, air will be circulated by the fans i2 over the finned element 20 and be discharged through outlets i into the room. Upon discontinuance of flow of .the heating medium or decrease in temperature thereof, below the desired degree, the temperature responsive switch means will act to open the circuit to the fans, thereby preventing the circulation of low temperature air. The fans therefore operate during the heating period only when the heat conveying medium is supplied at the desired temperature through the supply line and that the fan will entrance of outdoor air into chamber 4 for mix-' ing with the room air prior to contact with the heating element. I

During the heating season the switch 63 will be in open circuit position and the valve 43 will be in closed position, preventing flow of the cooling medium to the cooling element or coil 20. When it is desired to cool the air of the room and de-.

crease the relative humidity thereof the switch 63 is closed, completing the circuit of the solenoid valve which is then energized and opens to permit flow of the refrigerant to the cooling coil 20. When the switch 63 is closed, the solenoid valve 43 and fan motor l5 are in parallel circuit, the switch being shunt circuited or in parallel cir cuit with the fans and valve 43, and thus the fans operate continuously when the switch 63 is closed.

Since the supplying of the heating medium is discontinued when the cooling system is started, the heating element 2| will not heat the air circulated by the fans.

The automatic switch 35 bein when switch 63 is closed, in parallel circuit with fan motor IS, the operation of switch 35 will not ailect the fan motor circuit. The thermostatic expansion valve 39 operates in the usual manner to control the admittance of refrigerant to the cooling coil 20 to maintain the coil completely .refrigerated. Air is drawn into the compartment 4 by the fans and is circulated over the cooling coil and its extended fln surface. Some of the moisture in the air condenses on the cooling element 20 whence it drips into the container 45 and drains therefrom through drain pipe 52, the water inlet valve 54, of course, having been closed and the valve 53 having been opened.

From the foregoing description it will now be appreciated that I have provided a new and improved arrangement, in an electric circuit, of the control device and cooperating units of a combined heater and cooler unit. By arranging the fan, solenoid valve, temperature responsive switch and manual switch in circuit, as described, it will be seen that by closing the manual switch the solenoid valve and the fan will be in parallel circuit and the temperature responsive switch will be shunted, and that by opening the manual switch the fan and the temperature responsive switch will be in series circuit and the solenoid valve will be deenergized.

What I claimand desire to secure by Letters Patent of the United States is:

1. In an air conditioning system, a cooling element to which a cooling medium is supplied for passage therethrough, electrically operated valve means for controlling the flow of said cooling medium to said cooling element, a heating element to which a heating medium is supplied for passage therethrough, only one of said elements being in operation at the same time, a temperature responsive switch means in multiple circuit with said electrically operated valve, means, a fan controlled by said electrically operated switch means and in multiple circuit with said electrically operated valve means, said fan being operable to increase flow of air for heat exchange with both said heating element and said cooling element, said temperature responsive switch means being in heat transfer relation with said heating medium and operable during the heating season to close the circuit to said fan only when the heating medium is being supplied at a predetermined temperature to the said heating element, and a single switch means for controlling both the circuit of the electrically operated means and the operation of said fan by the temperature responsive switch means.

2. In an air conditioning system, a cooling element to which a cooling medium is supplied for circulation therethrough, an electrically operated valve for controlling flow to said cooling element, a heating element to which a heating medium is supplied for circulation therethrough, only one of said elements beingin operation at the same time, means for controlling flow of said heating medium to said heating element, a temperature responsive switch means in multiple circuit with said electrically operated valve, an electrically operated fan in multiple circuit with said electrically operated valve and in series circuit with said temperature responsive switch means for inducing circulation of air for heat transfer relation with both said heating and said cooling elements, said temperature. responsive switch means being in heat transfer relation with said heating mediunr for controlling the operation of said fan, and a single switch controlling the cir cult of said electrically operated valve and of said fan, said electrically operated valve being in closed circuit with said fan when said switch is in closed circuit position, said temperature responsive switch means being in closed circuit with said fan when said switch is in either open or closed position and said fan being in closed circuit in either position of said last-named switch means.

3. In an air conditioning apparatus, a. cooling element to which a cooling medium is supplied for passage therethrough, an electrically operated valve for controlling flow of the cooling medium to said cooling element, means regulating the temperature of said cooling element, a heating element to which a heating medium is supplied for passage therethrough, electrically operated fan means in parallel circuit with said electrically operated valve, said fan means being arranged to increase air fiow'for heat transfer relation with the cooling element and with the heating ele-' ment, a temperature responsiveswitch means in circuit with said fan means, said temperature responsive switch means being in heat transfer relation with said-heating medium to control the operation of the fan means so that the fan means will only operate during the heating-season when the heating medium is being supplied at a predetermined temperature to the said heating element, means for controlling the flow of said heating medium to said heating element, and a single switch controlling simultaneously both the circuit of the electrically operated valve and the operation of said fan means.

IRVING J. KNUDSON. 

